On the Season 7 DVD, there is a short deleted scene where the
camera pans up from Bart & Lisa in the basement to Homer & Marge in their
bedroom. There are termites in the floorboards between each of the floors.

Underground

As the townspeople mine down to rescue Bart, you can see a dinosaur skeleton, pirate's
treasure chest (and his skull), and an alien spaceship. The skeleton inside resembles
the standard Simpsons alien design like Kang/Kodos.

When the Simpsons fly to Australia, the camera pans down through the Earth. First we see
a set of coffins, in one of which the person was buried alive and tried to escape, then
some dinosaurs in coffins.

At the centre of the Earth, the Indian god Vishnu is
operating some controls. As we move back to the surface under Australia, remains of the
Skylab space station can be seen (debris from its re-entry in 1979 was scattered across
Western Australia).

In the future, Ms. Hoover reveals that Martin Prince had perished in a science fair
explosion. We then pan down, passing a skeleton torso, with one leg above him, then a treasure chest, then the skeleton's other leg.

Finally we reach Martin, dressed as the Phantom of the Opera, who says,
Not quite perished, my lady love, although some days I wish I had.